Extraction, ejection and ramming mechanism



July 5, 1955 P. H. DIXON ET AL 2,712,192

EXTRACTION, EJECTION AND RAMMING MECHANISM Figi- Filed OCT.. 2, 1951 lr'atenrted July 5, 1955 EXTRACTroN, EJECTIQN VAND RAMMING MECHANISM Faul H. Dixon and Maynard B. Wallin, Rockford, Ill., assignors to the United States of America as represented by the Secretary of the Army Appiication ctcber 2; 1951*, Serial No. 249,276

S Claims. (Cl. 424257) The present invention relates to a casel extraction and ejection mechanism for automatic guns. More particularly it relates to a case extraction and vejection mechanism used in conjunction with a self-locking shuttle type bolt in automatic cannons wherein the extraction and-ejection mechanism is mounted on the shuttle type bolt and operates automatically during bolt recoil after firing a round, and wherein the extraction and ejection mechanism serves the further purpose of ramming a freshv round into the chamber during the return travel of the shuttle type bolt assembly from the bolt buffer to the chamber.

It is accordingly an object of the present invention to provide a case extraction and ejection mechanism for use with a shuttle type bolt used in automatic cannons.

Another object of the present invention is to provide a simplied extraction and ejection mechanism which may be mounted directly on the shuttle type bolt of the automatic cannon and which operates automatically as a result of the recoil of the bolt.

A further object of the present invention is to provide a simple and e'itective extraction and ejection mechanism, which does notV require any additional actuating mechanism, but which utilizes the travel of the shuttle type bolt to render the mechanism effective in thev operation thereof.

A still further object of the present invention is to provide a simple mechanism which may be used for purpose of ramming as well as extraction and ejection of the cases.

The specic nature of the invention as well as other objects and advantages thereof will become obvious from the following description taken in connection with the accompanying drawing which show for purposes of illustration only one specific embodiment of the present invention, and wherein:

Figure 1 is a longitudinal, vertical sectional view of traction and ejection mechanism during ejection of a case.

Figure 5 is an enlarged fragmentary, longitudinal, vertical sectional view of the bolt assembly showing the extraction and ejection mechanism r'amming a new round of ammunition.

Figure 6 is a plan view partially in section of the extractor and its mounting.

Figure 7 is a cross sectional view of the extractor and its mounting taken along lines 7 7 of Figure 6.

Referring now more particularly to` the drawing wherein like reference numerals are used to designate like 5:1

parts in the various figures, reference numeral 1 designates the gun barrel or tube having a chamber 2 which receives the shell case 3. A breech ring 4 surrounds and is fastened to gun barrel 1 by means of threads (not shown). Breech ring 4 is provided on its upper side with a flat rack 5 which engages and actuates during recoil and counter recoil pinions of the feed mechanism (not shown); the particular feed mechanism forms no part of the present invention and is more fully described in the copending application to Paul H. Dixon, Serial Number 155,893, filed on April 14, 1950, entitled Feed Mechanism. A` receiver housing 6 open on its upper side to provide free access to rack 5 surrounds breech ring 4. The hollow interior of breech ring accommodates bolt stop ring 7 adjacent the rear end of the gun barrel 1. Two similar bolt lock inserts 8 are fastened to the hollow interior of breech ring 4 on both sides thereof adjacent bolt stop ring 7 by means of socket head cap screws 9 and breech ring insert screws 10. The sectional View of Figure 1 shows only one of the bolt lock inserts 8, the other one being mounted symmetrically in the breech ring opposite the one shown. Breech ring insert screws 10 extend through bolt lock inserts and further retain in position tube lock retainer 11, which is mounted intermediate the two bolt lock inserts 8 at the lower ends thereof. Tube locl: retainer 11 is provided with a keyway which receives tube lock 12 pvotally mounted in tube lock retainer 11 by means of tube lock pin 13. Tube lock 12 is urged torotate in a clockwise direction by means of spring 14. Tube lock 12 extends through bolt stop ring 7 and engages a recess in gun barrel 1 thereby preventing rotating of the latter during operation of the gun.

The bolt assembly consists of a bolt head 15 provided with bolt head locking cams 16, of an extractor ring 17 mounted on the rear end of bolt head 1S and kept in position thereat by retainer rings 18, of bolt body 19 having cross members 20, and of extractor 22. The bolt head locking cams 16 engage corresponding cams providedY in bolt inserts S to lock the bolt assembly in the breech ring during firing of a round. Sleeves 21 are mounted in cross members and support pistons (not shown) which are actuated in a rearward direction by the force of powder gases after tiring a round, thereby unlocking and accelerating the bolt assembly in a rearward direction' as is more fully described in the copending application to Paul H. Dixon and Maynard B. Walton, Serial Number 159,336, filed on May l, 1950, entitled Bolt Spline.

Recesses 23 and 24 (see Figs. 5 and 7) provided in bolt body 19 and in extractor ring 17 respectively seat extractor 22 which is pvotally mounted in extractor ring 17 Vby means of pivot pin 25. Pin 25 has flattened ends as indicated by reference numeral 26, thereby permitting only slidable movement of pin 25 in grooves 27 provided on opposite sides of recess 24 in extractor ring 17. The upper surface of extractor 22 is built up to form a cam 2S; the front end of extractor 22 is provided with an extractor lip 29 having bevelled edges 30 and 31, while the rear end thereof is provided with hook portion 34. Intermediate extractor 29 and hook portion 34 at the underside of extractor 22 protrudes ledge 32 having a bevelled edge 33; recess 4S on the upper side of bolt head 15 is provided to receive ledge 32. Bevelled edge 30, is cut at an angle of approximately 5l degrees with the vertical. The upper rear end of bolt body 19 is provided with step cut detents 35 and 36 which engage hook portion 34 as will be more fully described hereinafter.

Slider rails 37 guide the cross members 20 of the bolt lock 19 thereby preventing rotation of the bolt assembly during bolt recoil. Round support brackets 38 are securely fastened to receiver housing 6. Spring loaded round supports 39 are pivotally mounted on brackets 38. A chute 40 is provided at the underside of receiver housing 6 to guide the ejected case.

The forward end of bolt body 19 is inserted into a corresponding bore in bolt head 15. Helical splines 41, 42, 43 are provided on the surface of bolt body 19, and engage corresponding spline grooves (not shown) in bolt head 15. A spline stop ring 44 fastened in bolt head l5 by means of a snap ring 45 prevents disassembly of bolt head 15 and bolt body 19 during operation of the gun. Leaf spring 46, mounted in an appropriate recess in the upper surface of bolt body 19 urges the extractor in a clockwise direction thereby tending to raise hook portion 34 and to lower extractor lip 29. Reference numeral 47 designates a contact member through which an electrical contact is established for ring the gun as is more fully described in the aforementioned copending application, Serial Number 159,336. Bolt head 15 is provided on its upper side with recess 48 which receives ledge 32. Reference numeral 49 designates a groove in the rearward portion of shell case 3 which is used for purposes more fully described hereinafter.

In the operation of the extraction and ejection mechanism in accordance with the present invention, extractor lip 29 engages groove 49 of case 2 prior to ring of the round, when the bolt assembly is in its first locked position of smallest overall dimension and with barrel 1 in battery as illustrated in Figures l and 2. At that time bolt body 19 is halted in its forward movement within bolt head 15 by the splined end of bolt body 19 coming to bear against the inner bolt head face, as is more fully described in the aforementioned copending application, Serial Number 159,336. In other words, the total overall length of bolt body 19 and bolt head 15 is at a minimum, so that hook portion 34 of extractor 22 extends beyond the step cut detents in a rearward direction. Upon tiring of the round the bolt assembly will tend to recoil under pressure of the escaping gases applied to the bolt body 19 through the piston (not shownl'attached to sleeves 21. This will unlock the bolt assembly by converting the longitudinal rearward movement of bolt body 19 into rotational motion of bolt head 15 by means of the helical spline arrangement, thereby increasing the length of the bolt assembly until helical spline 41 comes to bear against spline stop ring 44. (See Figure 3.) The bolt assembly will lock in that extended condition constituting a second locked position of maximum overall dimension, and hook portion 34 engages thereupon step detent 35, while spring 46 assures proper engagement of extractor lip 29 with groove 49 of case 3. The bolt assembly will then accelerate as a unit in a rearward direction, with the bolt head and bolt body in the extended position, as more fully described in the last-mentioned copending application; hook portion 34 is locked against longitudinal movement by detent 35, and extractor lip 29 will extract case 3 as shown in Figure 3. After the bolt assembly together with case 3 has recoiled a certain distance, ejector cam 28 engages the under forward edge of the round supports 39 which lower the extractor lip 29, thereby driving case 3 downward as shown in Figure 4. This pilots case 3 out of the receiver ejection opening at an angle of about 2() degrees, ejecting the case via chute 40 which is connected to receiver housing 6 at the ejection opening thereof. With the hook portion 34 thus raised above step cut detent 35, extractor 22 together with pivot pin 25 will move in groove 27 relative to bolt assembly in a forward direction until bevelled edge 33 rests against the forward abutment of recess 48, as shown in Figure 4.

The bolt assembly continues in its rearward direction until it impinges on the bolt buffer assembly which brings it to a halt, reverses its direction of travel and accelerates the bolt assembly in a forward direction with a minimum of loss of energy. In the meantime a new round of ammunition is fed into ramming position and moved over -about half of its ramming distance by the rammer arms,

as is more fully described in the above-mentioned copending applications. Serial Number 155,893, and in the copending application to Paul H. Dixon and Maynard B. Wallin, Serial Number 156,574, led on April 18, 1950, entitled Round Rammer.

Because of the acceleration of the bolt assembly in a forward direction the extractor 22 together with pivot pin 25 will slide in a rearward direction in groove 27 during counterrecoil of the bolt assembly, thereby camming the extractor lip 29 to a proper level by bevelled edge 31 which forms an angle of about 45 degrees. This is caused by bevelled edge 31 engaging the edge of the bolt face. In that position hook portion 34 extends beyond step cut detent 3S. Upon collision by extractor lip 29 with the rear portion of the round to be rammed, as shown in Figure 5, bevelled edge 30 will cam up still further extractor lip 29, until it is raised above the rear portion of case 3; the bolt assembly continues to move in the forward direction whereby extractor lip 29 is caused to slide over the rear portion of case 3 until in line with groove 49 in case 3, whereupon spring 46, exerts sufcient spring pressure to force extractor lip 29 into groove 49. The face of the bolt assembly engages the rear end of case 3, and then completes the ramming of the round into chamber 2. When the bolt head 15 collides with bolt stop ring 7 it will lock the bolt assembly in its first position which will then take the position shown in Figures l and 2 as more fully described in the above-mentioned copending application, Serial Number 159,336. The bolt assembly together with the extraction and ejection mechanism is now ready again to repeatthe extraction and ejection cycle after firing a round.

While we have shown and described only one preferred embodiment of our invention it will be obvious to those skilled in the art that it is not so limited but is susceptible of various other changes and modifications without departing from the spirits thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

We claim:

1. In an extraction and ejection mechanism for use in automatic guns including a receiver and a shuttle ltype bolt assembly reciprocable therein in response to firing of the gun, said bolt assembly consisting of a bolt body portion having a step cut detent and a bolt head portion movable relative to each other and having a locked position at maximum overall length, an extractor pivotally mounted on said bolt head portion in slidable relation thereto for extracting and ejecting a shell case, said extractor comprising a lip means at its forward end for engaging a groove in said shell case during extraction, a hook means at its rearward end for engaging said step cut detent in said bolt body portion while in said locked position only, a cam intermediate said lip means and said pivotal mounting, and a cam engaging surface mounted within said receiver acting on said cam during rearward motion of said bolt assembly and extractor thereby ejecting said shell case, said extractor being provided with bevelled edges to cam up said lip portion during the forward return motion of said bolt assembly to a level sufficient to ram a new round of ammunition.

2. An extraction and ejection mechanism for use in an automatic gun including a receiver and a shuttle type bolt assembly reciprocable therein in response to ring of the gun, said bolt assembly consisting of a bolt body portion having a detent and a bolt head portion movable relative to each other a limited distance and having a locked position of maximum overall length, comprising an extractor for extracting and ejecting a shell case from the chamber of said gun, said extractor being pivotally mounted on said bolt head portion in slidable relation thereto and including a lip means at its forward end at all times extending beyond said bolt head portion, a hook means at its rearward end engaging said detent in said bolt body portion only with said assembly in its locxed position, and a cam protruding from its upper surface intermediate said lip means and said pivotal mounting.

3. The apparatus according to claim 2 wherein said extractor further comprises ledge means protruding from the lower side thereof.

4. The apparatus according to claim 3 wherein said lip means and ledge means are provided with bevelled edges.

5. The apparatus according to claim 4 further comprising spring means between said extractor and said bolt assembly urging said extractor in a clockwise direction.

6. In an automatic gun a device for extracting and ramming shells comprising a bolt assembly reciprocatable therein, said bolt assembly comprising a bolt body and a bolt head nesting together in rotatable intertting relation to change the length thereof during reciprocaton, a step detent formed on said bolt body, an extractor mounted for limited rotation and translation on said bolt-head, the upper surface of said extractor shaped to form a cam.y the lower surface of said extractor shaped to form a lip and a hook at respective ends thereof whereby in battery position the said lip engages a shell and the said bolt body and the said bolt head interlit to define a minimum length, and in recoiling position the said length is a maximum to engage the said hook in the said step detent until the said cam engages a cam engaging surface to rotate said extractor and force the said shell out of the gun, said extractor being provided with bevelled edges to cam up said lip during forward return motion of said assentbly to a level sufficient to ram a round of ammunition.

7. In an automatic gun a device for extracting shells comprising a bolt assembly reciprocatable therein, said bolt assembly comprising a bolt body and a bolt head nesting together in intertting relation to denne a mink mum length in battery position and a maximum length during reciprocation, a step detent formed on said bolt body, an extractor mounted for limited rotation on said bolt head, the upper surface of said extractor shaped to form a cam to cooperate with a cam engaging surface to pivot said extractor to eject the shell during rearward motion thereof, the lower surface of said extractor shaped to form a lip on one end thereof to engage a shell and a hook on the other end thereof to engage the said step detent formed in said bolt body to loci; said bolt body and bolt head in their relation of maximum length during reciprocation.

8. ln an automatic gun a device for extracting and ramming shells comprising a bolt assembly reciprocatable therein, said bolt assembly comprising a bolt body and a bolt head nesting together in interiitting relation to dene a minimum length in battery position and a maximum length during reciprocation, a step detent formed on said bolt body, an extractor mounted on said bolt head for rotation and translation with respect thereto, the upper surface of said extractor shaped to form a cam to coop rate with a cam engaging surface to pivot said extractor to eject the shell during rearward motion thereof, the lower surface of said extractor shaped to form a lip on one end thereof to engage a shell and a hook on the other end thereof to engage said step detent to lock the said bolt assembly during reciprocation, spring means between said bolt body and said extractor to insure proper engagement of said lip with the shell during extraction, the said extractor being provided with bevelled edges to cam up said lip during forward motion of said assembly to a level sufficient to ram a new round of ammunition.

References Cited in the file of this patent UNTTED STATES PATENTS 617,943 Weisheit Ian. 17, 1899 790,615 Burton May 23, 1905 1,090,351 Swebilius et al. Mar. 17, 1914r 1,454,039 Chevallier May 8, 1923 2,458,028 Rataiczak Jan. 4, 1949 2,465,553 Robinson Mar. 29, 1949 FOREIGN PATENTS 555,263 Great Britain Aug. 13, 1943 

